1. Field of the Invention
The present invention generally relates to a shifter for the actuation of a derailleur on bicycles. The shifter for a derailleur for bicycles comprises a housing, a detent element which is connected both to the manual actuator and to the derailleur, as well as a detent spring made of elastic plastic material, the lug of which interacts with detents of the detent element and can have a transition distance between the housing and the detent spring.
2. Background Information
French Patent No. 2 657 062 discloses a shifter for derailleurs which has a rotating ring 44 with a cable suspension 43 and grip ends 50 as well as a housing 22 fastened to the handlebar with notches for a spring ring 28 which interacts by means of lugs 26 with notches 46 in the rotating ring 44. This spring ring 28 is realized in one piece as shown in FIG. 2 and in two parts as shown in FIG. 4, whereby one of the parts is the detent spring 29, which can be rotated by a small circular distance relative to the second ring part 29'. This relative rotational capability, as disclosed in claim 6, makes it possible to increase the shifting travel from one detent to the next, against the spring force of the derailleur, by just this small relative rotation, whereby a transition travel is produced which, when the chain is shifted from a smaller sprocket to the next larger sprocket, can be used as before to significantly improve the shifting quality.
An improvement could be made by introducing a transition spring which would be installed as a compression spring in the transition space between the detent spring and the second ring part or the housing. The advantage would lie in a defined position of the detent spring in the idle position of the shifting system and in the precision of shifting which could be achieved after shifting from the smaller to the next larger sprocket by the momentary neutralization of the transitional condition.